Conventionally, a multi-directional switching device has been known which includes a plurality of switching elements mounted on a printed-circuit board, a casing including the switching elements therein, a swiveling operation knob supported on a top panel of the casing, and a plurality of drive members interposed between the operation knob and the respective switching elements, and which converts the rotational movement of the operation knob oscillated and operated by a user into the linear movement through one of the drive members and transmits the linear movement to the corresponding one of the switching elements (refer to Japanese Unexamined Patent Application Publication No. 2000322981, for example). The above switching elements are formed by a so-called rubber switch, for example, which includes a plurality of fixed contacts provided on the upper surface of the printed-circuit board and movable contacts provided on the inner bottom surfaces of a plurality of projections integrally formed with an elastic member, such as rubber. The drive members are provided to a plurality of cylindrical members hanging from the top panel of the casing, and are inserted in respective guide holes to be capable of ascending and descending. Since the lower end of each of the drive members is formed with a flange portion larger in diameter than the corresponding guide hole, the drive member is prevented from escaping upward from the guide hole. Further, the lower ends of the respective drive members are in contact with the upper surfaces of the corresponding projections of the switching elements. With the flange portions of the drive members connected with one another by elastic arm members, the plurality of the drive members can be handled as one integrated part.
When the multi-directional switching device configured as summarized above is in a non-operational state in which the operation knob is not oscillated and operated, the respective drive members are projected from the upper ends of the corresponding guide holes under the biasing force applied by the projections of the switching elements, and the operation knob is kept at the neutral position under the equal force applied by the respective drive members. In this state, if the user oscillates and operates the operation knob in an arbitrary direction, the drive member located in the direction is selectively pressed by the operation knob and descends in the corresponding guide hole. Thereby, the projection located below the drive member is buckled and deformed to place the corresponding switching element into the ON operation. In this process, the upper end of the drive member located 180 degrees opposite the oscillation direction is separated from the operation knob. However, the flange portion of the drive member receives the biasing force applied by the corresponding projection and comes into contact with the lower end of the corresponding cylindrical member. Thus, the drive member is prevented from rattling due to external vibration. When the above control force on the operation knob is removed, the pressed drive member is raised by the restoring force of the buckled and deformed projection. Accordingly, the switching element switches from the ON state to the OFF state, and the operation knob returns to the original neutral position.
In the conventional multi-directional switching device configured as described above, the respective drive members formed with the flange portions at the lower ends thereof are biased toward the upper parts of the guide holes by the elastic force of the switching elements. Therefore, even if the upper end of an arbitrary one of the drive members is separated from the operation knob in the oscillating operation of the operation knob, the movement of the drive member in the upward and downward directions is controlled, with the flange portion of the drive member in contact with the lower end of the corresponding cylindrical portion. Thus, the drive member is prevented from rattling due to the external vibration or the like and from generating abnormal noise. In the assembly process of the multi-directional switching device, however, the operation knob is attached to the top panel of the casing, and thereafter the casing is turned upside down to insert the drive members to the guide holes of the respective cylindrical members. This inevitably makes the direction of attaching the operation knob to the casing opposite to the direction of attaching the drive members to the casing, which has been a major factor preventing the automation of the assembly process. Meanwhile, the flange portions formed at the lower ends of the respective drive members are connected to one another by the elastic arm members, and thus the plurality of the drive members can be inserted in the corresponding guide holes at the same time. Although the multi-directional switching device has such an advantage, when an arbitrary one of the drive members descends through the oscillating operation of the operation knob, the descending of the drive member affects the elastic arm members and makes the other drive members tend to descend together with the drive member. This may trigger such phenomena as the malfunction of the switching elements and the deterioration of the operation feeling in operating the switching device.